At CB address your stroking hand should be directly below your elbow - and both hand and elbow should be in the same vertical plane as your shoulder.
I think we probably mean the same thing.
pj
chgo
I'm a fixed elbow guy so my grip hand isn't under my shoulder until well into my follow through, after the CB is gone.pj...
I think the stroking hand should be close to under your shoulder when the cue tip is near the CB.
Where your cue is before stroking at the CB is when (as you said) your hand is below the elbow.
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With my grip hand under my elbow (at CB address), my forearm is about perpendicular to the cue - that's where the arc of my grip hand's movement during the stroke is mostly "level" for the longest time, giving the most room for vertical tip placement error, so that's where I want to be hitting the CB.
I think that's pretty standard fixed elbow stroke rationale.
On the other hand, I think the stroke's natural peak power might come a little after that vertical-forearm point - maybe why we see players move their grip hands forward for breaking. That could make a difference in the feel of the stroke for some.
pj
chgo